gcelaya

I wanted to have a stealth box but did not want to spend $600 (JL) or even $200+ (Ebay) for one. I decided to do it myself, just for fun.

First, clean the surrounding side panel of the car with alcohol or wax-sticky remover. Even after cleaning the panel had a very hard time holding tape. You want to totally coat the entire surround with tape, and dont be cheap. Use too much. In fact, in certain areas the tape would not hold (blue masking) and I found that the only tape that would stick was the foil tape to seal metal ductwork from Home Depot. What ever the case, tape it like crazy. After that you need to draw an outline with a big fat black marker of the box that you want on that tape. I just looked at the JL box and went from there.

Next apply release agent or ? I used WD40 and sprayed it generously and rubbed it in. It worked OK, but I would have liked a better release.

I bought the resin ($35.xx) and 4 packages of fiberglass mat ($28.xx) from Home Depot. Dont forget disposable brushes and many pair of disposable exam gloves. You will need them. Take the mat and tear it up into many pieces about 3X5 in size.

I then mixed up the resin and painted the surface of tape and stuck on many pieces of fiberglass. make sure that they overlap. Then take your brush and aggressively dab resin into the glass. Make sure that you saturate the glass fully with resin. You will need to move fast because the resin will start to harden relatively fast. I found that for my temp (68 deg) 4 oz was a perfect amount to work with and then repeat with another 4 oz. I would stay about 1 inch away from your outline line. In other words, you want to be short (I did not do this and had a hard time getting it to release). Keep working. Get many coats of glass and resin. You do not want it to be weak. I applied 5 to 7 coats of glass. you are satisfied let it harden and then peel it off. It might take a little persuasion to get it off. Some of the tape did come off and was in bedded in the glass, but no big deal (that was the short fall of the WD40 as a release agent).

I then made a template for the front, two sides, and top out of carbboard. Once I got the proper fit I traced it onto cabinet grade plywood and cut it out with a jigsaw and made sure that it properly fit against the interior side panel. I glued and screwed the sides to the front and also put a 1x1 square piece of filler at the junctions where they met. This will give you plenty of material when you round the corners of the box with a router and roundover bit. If you dont have this you can always use a sander, but it will take you some time. Make sure that the box fits the contour of you side panel before you go any further.

Once you are happy with the fit, place the already separated hardened glass structure that you already built back into the side panel mold. You will then take more glass and resin and start to fiberglass (as described above) it just past your outline mark. Do a few coats. Work fast. Then you are satisfied take your wood structure that you built and press it into place on top of the new undried glass. Put something resting on the box or prop up a pole to keep pressure on the box to make sure it gets a tight mate with the glass. Your goal is to mate the wood box and the molded glass. Let it dry completely and peel it off. Then cut off any remaining glass material on the front, top, and sides. If you do all your glass at one time and bond the wood box to the glass in that process, separating it becomes a really big deal. That is why you do it in two steps and separate it after the 1st step. I then figured out what size speaker that I wanted and where to put it on the front of the box. (before I screwed the case together, I placed it in the location and filled it up with popcorn. I then took all the popcorn out and measured it to .70 cu ft. I wanted to get the proper speaker for the size enclosure. Every speaker guy told me that that is not that important. I looked at JL's setup and their speaker that comes in the stealthbox does not match what they suggest, as their box is roughly the same size as the one I built). I cut a hole with a jig saw for a 12" CVR Kicker. There is more than enough space for the depth of that speaker if you line it up right to fit in the cuby hole of the side panel. After cutting the opening of for the speaker and getting it open, I continued to fiberglass the back glass to the wood sides and top from the inside. Make sure that you get enough material and resin to fill in any holes and bond the entire thing as one piece. Dont forget to do all 4 sides. I also cut out for the terminal connectors. I put it where the speaker box goes over the cuby hole on the floor. Solder your connections inside the box using a wire about a foot long. I then connected the speaker by soldering wire to the terminals from the box terminal to the speaker terminal paying attention to positive and negative Dont solder the wire onto the speaker yet. Do this later on your final speaker install. I then temporarily mounted the speaker. I used blind t-nuts. Not too thrilled with those. I am not sure if I would do that again or just use wood or drywall screws to mount the speaker.

I then covered the front, sides, top, and some of the back with box carpet bought at a stereo shop. I stuck it on with 3m 77 from Home Depot. I did not do the entire back, just some parts to stop rubbing, because the box would not fit properly as the carpet would take up too much space and off set the fit. I then went on JL site and took a look at their box mounting instructions and followed them. I drilled a hole in the same location and when I went to push the screw through from the fender side, I noted that there was a hole already drilled there but covered with under covering. If I were to do it over again, I would drill it from the outside in and find that already drilled hole. Before you mount the speaker, you need to take a hole saw and drill the inside panel where you drilled your screw mounting hole. You will need to place a spacer between your box and the metal of the car because the side panel is about an inch away from the metal fenderwell. I used washers stacked up and it worked fine. Ran the wires into that cuby hold on the floor and attached the wires to the terminal and then to the amp and then bolted the box in. It fit very nice and snug.

I soldered the inside wires to the speaker and then mounted the speaker and grill cover. I hooked it up to a 600 watt amp. This is way more bass that you are ever going to need. It shakes and vibrates the windows enough that is makes you sick. You will definitely not need any more, and could probably get away with a 10" speaker. I can always turn the bass down.

buickid

I respectfully disagree and advise you not to ride in my car

All joking aside, nice job! Perfect for anyone that needs a trunk and still wants some bump

xseveredveganx

^^^I agree. But I'm a competitor... 145db's doesn't phase me. Mid 150's is about my breaking point. If I stop giggling.

Looks good, bro!!!

KaneoheKoa

Great job! Looks as good as any custom shop. Personally, I dislike fiberglass (well, I dislike the fiberglass itch!). Don't worry about having "too much amp" for the sub. If you're overdriving it, the sub will let you know. More power is better, because you have more reserves when the music requires a harder hit. Underpowering a speaker usually leads to a blown speaker. Again, masterful work!

Oh, by the way, I don't recommend using drywall screws for speaker mounting into plywood. T-nuts are good, but you need to use a c-clamp to press them into the speaker baffle so they mount flush and straight. Threaded inserts are good, too. A small drop of thread lock on the mounting bolt keeps it secure. If you want to get fancy, use stainless steel round head hex socket machine screws.